Poison baits are well known as being useful in controlling insects such as cockroaches, ants and the like. Such poison baits typically contain an edible composition that provides control over the insect after said insect has ingested the poison bait. Since the poison baits also generally contain a insecticidal compound, there is typically a greater insect controlling activity associated with said baits when large quantities of insects ingest said baits, and conversely a smaller insect controlling activity when a smaller quantity of insects ingest said baits.
Gelled poison baits are proposed since they are suitable for applying on vertical plane. GB-2336111 and WO 91-07972 describe poison baits which comprise carrageenan as an insect attractant as well as a gelling agent. Carrageenan is effective attractant; however, a poison bait that is practically useful should comprise a fat and/or fatty oil.
On the other hand, JP 2000-53505A discloses an aqueous bait comprising 1-methyl-2-nitro-3-[(tetrahydrofuryl)methyl]guanidine, which is an insecticidal ingredient and described in EP-649845A. The insecticidal ingredient, 1-methyl-2-nitro-3-[(tetrahydrofuryl)methyl]guanidine, is water-soluble and easily formulated to an aqueous solution for bait. However, it was difficult to obtain a gelled bait comprising a fat and/or fatty oil that is effective for controlling harmful insects constantly for a long time. It may come from the hydrophilicity of the insecticidal ingredient in fat or fatty oil.